International Journal of Oral Implantology, 04/2013

A case report of severe bleeding after sinus floor elevation using the transcrestal approach was published in EJOI in the third issue of 2012 by Dr Simon Storgård Jensen and coworkers1. EJOI has received a letter regarding this case report from Dr Federico Mandelli and Dr Tiziano Testori. EJOI has decided to publish this letter together with the answers from the authors as well as minor comments from the EJOI editors. It is our hope that the letter and the reply will provide readers with improved interpretation and understanding of the case report presented. Marco Esposito, Jerome Lindeboom, Søren Schou

Purpose: To compare two different impression techniques for implants in totally edentulous patients. Materials and methods: A total of 38 patients had impressions taken both using plaster and splinted vinyl polysiloxane (splinted-VPS). Two casts per patient were generated and allocated as test (plaster) and control (splinted-VPS) cast groups according to a randomised cross-over design. One of the two casts from each patient was randomly selected as master cast according to a parallelgroup design and used to fabricate the definitive prosthesis. Outcome measures were implant and prosthetic success rates, complications, marginal bone level (MBL) changes, patient satisfaction, chair time required to take the impressions, inter-implant discrepancy between the casts, sulcus bleeding index (SBI) and plaque score (PS). Results: In total, 76 impressions were taken in 38 patients. Two plaster impressions failed. Furthermore, 38 computer-aided design/computer-assisted manufacturing screw-retained complete-arch prostheses were fabricated onto the master cast (18 from plaster and 20 from splinted-VPS impressions) and the patients were followed up for 3 years after loading. No drop-out occurred and no implants or prostheses failed, accounting for a cumulative implant and prosthesis survival rate of 100% over the 3-year post-loading period. Plaster impressions yielded significantly greater patient satisfaction and shorter chair time. The discrepancy between the casts was 0.055 ± 0.067 mm (P = 0.931). Mixed model analysis revealed a significant main effect from both the implant number and the inter-implant distance, while no difference was found with regard to implant angulation. Five chip-off fractures of the porcelain veneer occurred in 5 of the 38 patients (3 in restorations fabricated onto the plaster cast group and 2 in the splinted-VPS cast group) with no effect from the type of impression on the prosthetic success rate (P = 0.331). However, all of the patients were functionally and aesthetically satisfied with their prostheses. Furthermore, mean MBL, SBI and PS showed no significant differences (P > 0.05) between the groups. Conclusions: The clinical outcome of plaster impressions for completely edentulous patients was found to be the same as that for splinted-VPS impressions. The intraoral pre-scan resin framework try-in can be avoided. Plaster impressions may be less time consuming and thus more comfortable for the patient, but sometimes may have to be repeated due to fractures. Keywords: CAD/CAM, fully edentulous, implant impressions, optical scanning Conflict-of-interest statement: All materials used in this study were purchased by the authors and there were no commercial or institutional interests.

Purpose: To evaluate whether 5 × 5 mm dental implants with a novel nanostructured calciumincorporated titanium surface could be an alternative to implants at least 10 mm long placed in bone augmented with bone substitutes in posterior atrophic jaws. Materials and methods: A total of 40 patients with atrophic posterior (premolar and molar areas) mandibles having 5 to 7 mm of bone height above the mandibular canal and 40 patients with atrophic maxillae having 4 to 6 mm below the maxillary sinus, were randomised according to a parallel group design to receive one to three 5 mm implants or one to three at least 10 mm-long implants in augmented bone at two centres. All implants had a diameter of 5 mm. Mandibles were vertically augmented with interpositional bovine bone blocks and resorbable barriers. Implants were placed after 4 months. Maxillary sinuses were augmented with particulated porcine bone via a lateral window covered with resorbable barriers and implants were placed simultaneously. All implants were submerged and loaded after 4 months with provisional prostheses. Four months later, definitive screw-retained or provisionally cemented metal-ceramic or zirconia prostheses were delivered. Patients were followed up to 1 year post-loading and the outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone level changes. Results: One maxillary grafted patient dropped out before the 1-year evaluation. In mandibles, 1 grafted patient did not want to go ahead with the treatment because of multiple complications and graft failure, and another grafted patient did not receive his prostheses due the loss of 2 implants. In maxillae, one 5 × 5 mm implant failed with its provisional crown 3 months post-loading. There were no statistically significant differences in prostheses and implant failures. Significantly more complications occurred at both mandibular and maxillary grafted sites: 17 augmented patients were affected by complications versus 8 patients treated with short implants in the mandible (P = 0.0079; difference in proportion = -0.45; 95% CI -0.67 to -0.15), and 5 sinus-lift patients versus none treated with maxillary short implants (P = 0.047; difference in proportion = -0.25; 95% CI -0.44 to -0.06). Patients with mandibular short implants lost on average 0.94 mm of peri-implant bone at 1 year and patients with 10 mm or longer mandibular implants lost 1.03 mm. Patients with maxillary short implants lost on average 0.87 mm of peri-implant bone at 1 year and patients with 10 mm or longer maxillary implants lost 1.15 mm. There were no statistically significant differences in bone level changes up to 1 year between short and longer implants in maxillae (mean difference -0.28 mm, 95% CI -0.56 to 0.01, P = 0.051) and in mandibles (mean difference -0.09 mm, 95% CI -0.26 to 0.08, P = 0.295). Conclusions: One year after loading, 5 × 5 mm implants achieved similar results compared to longer implants placed in augmented bone. Short implants might be a preferable choice to bone augmentation especially in posterior mandibles since the treatment is faster, cheaper and associated with less morbidity, however 5 to 10 years of post-loading data are necessary before making reliable recommendations. Keywords: bone substitutes, inlay graft, short dental implants, sinus lift, vertical augmentation Conflict-of-interest statement: MegaGen partially supported this trial and donated implants and prosthetic components used in this study, whereas Tecnoss donated the biomaterials. The data belonged to the authors and by no means did the manufacturers interfere with the conduct of the trial or the publication of its results.

Purpose: To evaluate whether 6 mm long by 4 mm wide dental implants could be an alternative to implants at least 10 mm long placed in bone augmented with bone substitutes in posterior atrophic jaws. Materials and methods: A total of 20 patients with bilateral atrophic mandibles and 20 patients with bilateral atrophic maxillae, having 5 to 7 mm of bone height above the mandibular canal or below the maxillary sinus, had each side of the jaws randomly allocated according to a split-mouth design. They were allocated to receive one to three 6 mm long and 4 mm wide implants, or implants at least 10 mm long in augmented bone by two different surgeons in different centres. Mandibles were vertically augmented with interpositional equine bone blocks and resorbable barriers, and implants were placed 3 months later. Maxillary sinuses were augmented with particulated porcine bone via a lateral window and implants were placed simultaneously. All implants were submerged and loaded, after 4 months, with provisional prostheses. Four months later, definitive metal-ceramic prostheses were delivered. Outcome measures were prosthesis and implant failures, any complication and radiographic peri-implant marginal bone level changes. Results: One patient treated in the mandible dropped out before the 1-year post-loading follow-up. All maxillary implants and prostheses were successful, whereas 2 mandibular prostheses could not be placed on implants at least 10 mm long due to graft failures; one was associated with the loss of 3 implants because of infection. There were no statistically significant differences in implant and prosthesis failures, though significantly more complications occurred at grafted sites in mandibles (P = 0.0078), but not in maxillae (P = 0.1250). In total, 14 complications occurred in 12 patients at augmented sites versus none at 6 mm-long implants. All failures and complications occurred before loading. Patients with mandibular 6 mm-long implants lost an average of 1.05 mm of peri-implant bone at 1 year and patients with mandibular implants at least 10 mm long lost 1.07 mm. These differences were statistically significant (P < 0.001). Patients with maxillary 6 mm-long implants lost an average of 1.02 mm of peri-implant bone at 1 year and patients with maxillary implants at least 10 mm long lost 1.09 mm. These differences were statistically significant (P < 0.001). There were no statistically significant differences in bone level changes up to 1 year between 6 mm and at least 10 mm-long implants in both jaws (mandibles n = 18, mean difference -0.02 mm, 95% CI -0.16 to 0.12, P = 0.7384; maxillae n = 20, mean difference -0.07 mm, 95% CI -0.18 to 0.05, P = 0.2547). Conclusions: Short-term data (1 year after loading) indicate that 6 mm-long implants with a conventional diameter of 4 mm achieved similar if not better results than longer implants placed in augmented bone. Short implants might be a preferable choice to bone augmentation, especially in posterior mandibles since the treatment is faster, cheaper and associated with less morbidity. However, data obtained 5 to 10 years after loading are necessary before making reliable recommendations. Keywords: bone substitutes, inlay graft, short dental implants, sinus lift, vertical augmentation Conflict of interest statement: Tecnoss and Southern Implants partially supported this trial and donated biomaterials, implants and prosthetic components used in this study. However, the data belonged to the authors and by no means did the manufacturers interfere with the conduct of the trial or the publication of its results.

Purpose: The aim of this prospective study is to evaluate the outcome of the bony lid approach in pre-implant and implant surgery. Materials and methods: A total of 200 consecutive patients were treated between 2003 and 2008 with the bony lid technique in a prospective study and followed up for at least 4 years. The bony lid approach consisted in cutting and luxating a bony lid using a microsaw, which was then repositioned at the end of the surgery to avoid large bone defects in the case of osteotomies. In 146 cases the bony lid approach was used for implant explantation, in 29 cases for removal of fractured roots or foreign bodies from the implant site, in 14 cases for removal of impacted teeth from the implant site, in 4 patients in combination with nerve decompression/nerve lateralisation, and in 7 cases for removal of implants from the sinus. In 76 patients, the bony lid technique was performed simultaneously with the implant insertion or bone grafting procedure. In the remaining 124 cases, the bone grafting procedure/implant insertion was performed 3 months postoperatively. Outcome measures were success of the procedure, complications and stability of the bone volume of the alveolar crest. Results: All of the bony lid procedures obtained the desired aim and healed without any complication. The re-entry showed, in most cases (98.5%), a well integrated vestibular bone wall with volume stability. The average width of the alveolar crest after the reimplantation of the bony lid was 7.6 ± 0.8 mm in 124 patients, where the bony lid was reimplanted without simultaneous implantation/augmentation. At the re-entry 3 months later, an average width of 7.1 ± 1.2 mm was observed. In the 76 patients where the bony lid was reimplanted simultaneously with the implant insertion or with the bone grafting procedure, normal healing without any infection was observed. Only 3 cases demonstrated important volume changes, all in the 2-stage group. In all patients, it was possible to continue the treatment as planned. Conclusion: The results of the present study showed good outcomes for the bony lid approach. Keywords: bone graft, bone reimplantation, bony lid, diamond disc, microsaw Conflict-of-interest statement: This study was completely self-supported and no contribution from any commercial party was received, even in the form of free materials.

Purpose: To assess patient satisfaction and aesthetic treatment outcome of implant-supported singletooth replacements performed by dental students as part of their undergraduate curriculum 8 to 12 years after treatment. Materials and methods: A total of 51 patients were consecutively treated by dental students with 55 implant-supported single-tooth replacements within the incisor, canine and premolar regions. The surgical and prosthetic treatment was performed by the dental students under the supervision of dentists and oral and maxillofacial surgeons, all with specific knowledge about oral implantology. The outcome measures were patient subjective evaluation of peri-implant soft tissues, implant crown, implant function and total implant treatment using a Visual Analogue Scale (VAS). The professional evaluation included the peri-implant soft tissues, implant crown and total implant treatment (combined scores, PES/WES) using the Pink Esthetic Score (PES) and the White Esthetic Score (WES), as well as the level of incisor edge/occlusal surface in relation to neighbouring teeth. Results: A total of 42 patients with 46 implants were available for evaluation 8 to 12 years after treatment. The patients were in general satisfied with the treatment outcome and few patients had low VAS scores. Most implants were characterised by single scores of 1 or 2 resulting in a mean PES score of 8.3 (maximum 14), a mean WES score of 6.3 (maximum 10) and a mean PES/WES score of 14.6 (maximum 24). However, 33% of the implants were characterised by recession (>1 mm) of the facial soft-tissue margin. Correlation analyses involving the subjective parameters indicated that the evaluation of the total implant treatment was mainly influenced by the appearance of the implant crown and to a lesser extent by the peri-implant mucosa. There were no significant correlations between the subjective and professional evaluation. Both the subjective and professional evaluation revealed implants in infraposition. This was registered in 7% and 17% of the implants, respectively. Conclusions: The patient satisfaction and aesthetic outcome 8 to 12 years after treatment with implant-supported single-tooth replacements performed by dental students as part of their clinical undergraduate dental curriculum were characterised by high patient satisfaction and an acceptable aesthetic treatment outcome. Therefore, it seems acceptable to include implant therapy of straightforward cases in the clinical undergraduate curriculum, provided there is substantial supervision by trained clinicians. Keywords: dental aesthetics, dental implants, dental students, oral implants, patient satisfaction, retrospective study, treatment outcome Conflict-of-interest statement: The study was partially supported by Nobel Biocare, Denmark. There was no conflict of interest.